Goldberg, a former press secretary to a governor of Maryland, invented the day. Since the beginning of the month began with telling lies on April Fool’s Day, Goldberg felt the month should end on a higher moral note, according to Holidayinsights.com.

Although it’s referred to as a national day, Holiday Insights did not find any congressional records or presidential proclamations for April 30.

Regardless, on this day people are encouraged to tell the truth for 24 hours.